I have a flight from Canada to China (by aircanada). It seems that I can't bring pepper spray to the plane, but can I consign it? Is that illegal?
Given pepper spray is considered illegal by the Chinese government, you may well be able to consign it, but it would be confiscated at destination and you may run into problems with being accused of trying to import illegal items.
Example in Hong Kong (I realise that's not mainland China but a quick search reveals many indicators that it's illegal through mainland China as well)